The improvements include:
- Allowing overset patches to be displaced outside background domain.
- The approach does not support overlapping of multiple inset meshes
on top of background domain.
- Allowing fringe faces to walk away from hole cells in background domain.
- The approach was not extensibly tested with overlapping patches.
- Improving mass conservation.
- Various experimental entries are removed: massFluxInterpolation, ddtCorr.
- New entries:
- oversetAdjustPhi: adds a flux correction outside the pressure equation.
- massCorrection: adds an implicit correction.
- rename effectivenessHeatExchangerSource -> heatExchangerSource
- introduce submodels:
- effectivenessTable (previous behaviour)
- referenceTemperature
- the referenceTemperature submodel uses a reference temperature
which is either a scalar or calculated from a 2D interpolation
table in order to calculate the heat exchange.
speciesSorption is a zeroGradient BC which absorbs mass given by a first
order time derivative, absoprtion rate and an equilibrium value
calculated based on internal species values next to the wall.
patchCellsSource is a source fvOption which applies to the corresponding
species and apply the source calculated on the speciesSorption BC.
A new abstract virtual class was created to group BC's which
don't introduce a source to the matrix (i.e zeroGradient) but calculate
a mass sink/source which should be introduced into the matrix. This
is done through the fvOption patchCellsSource.
- avoid any operations for zero sources
- explicit sources are applied to the entire mesh can be added directly,
without an intermediate DimensionedField
- update some legacy faMatrix/fvMatrix methods that used Istream
instead of dictionary or dimensionSet for their parameters.
Simplify handling of tmps.
- align faMatrix methods with the updated their fvMatrix counterparts
(eg, DimensionedField instead of GeometricField for sources)
- resizes to current fieldNames_ size and assigns everything to
false to avoid any "stickiness" if the field ordering changes
between reads.
ENH: additional debugging faOption/fvOption (#2110)
- aids tracing which sources are being used/ignored
- update code style
STYLE: rename CodedSource -> CodedFvSource
- avoid future name clashes with CodedFaSource
Applies sources on turbulent kinetic energy (i.e. `k`)
and either turbulent kinetic energy dissipation rate (i.e. `epsilon`)
or specific dissipation rate (i.e. `omega`) to incorporate effects
of buoyancy on turbulence in incompressible and compressible flows.
See buoyancyTurbSource.H for details.
See GL #1433
Applies corrections to turbulence kinetic energy equation and turbulence
viscosity field for incompressible multiphase flow cases.
Turbulence kinetic energy is over-predicted in VOF solvers at the phase
interface and throughout the water column in nearly-potential flow regions
beneath surface waves.
This fvOption applies corrections based on the references:
Buoyancy source term in turbulence kinetic energy equation:
Devolder, B., Rauwoens, P., and Troch, P. (2017).
Application of a buoyancy-modified k-w SST turbulence model to
simulate wave run-up around a monopile subjected to regular waves
using OpenFOAM.
Coastal Engineering, 125, 81-94.
Correction to turbulence viscosity field:
Larsen, B.E. and Fuhrman, D.R. (2018).
On the over-production of turbulence beneath surface waves in
Reynolds-averaged Navier-Stokes models
J. Fluid Mech, 853, 419-460
Example usage:
multiphaseStabilizedTurbulence1
{
type multiphaseStabilizedTurbulence;
active yes;
multiphaseStabilizedTurbulenceCoeffs
{
// Optional coefficients
lambda2 0.1; // A value of 0 sets the nut correction to 0
Cmu 0.09; // from k-epsilon model
C 1.51; // model coefficient from k-omega model
alpha 1.36; // 1/Prt
}
}
Thanks go to the Turbulence Technical Committee, and the useful discussions
with and code testing by Bjarke Eltard-Larsen and David Fuhrman (Technical
University of Denmark).
- Eg, with surface writers now in surfMesh, there are fewer libraries
depending on conversion and sampling.
COMP: regularize linkage ordering and avoid some implicit linkage (#1238)
- Arrhenius viscocity model for incompressible viscocity.
- energyTransport FO for incompressible single and multiple phase
flows and viscousDissipation fvOption source.
- Tutorial to show the use of energyTransport:
multiphase/multiphaseInterFoam/laminar/mixerVessel2D
- Tutorial to show viscousDissipation:
compressible/rhoPimpleFoam/RAS/TJunction
Evolves an electrical potential equation
\f[
\grad \left( \sigma \grad V \right)
\f]
where \f$ V \f$ is electrical potential and \f$\sigma\f$ is the
electrical current
To provide a Joule heating contribution according to:
Differential form of Joule heating - power per unit volume:
\f[
\frac{d(P)}{d(V)} = J \cdot E
\f]
where \f$ J \f$ is the current density and \f$ E \f$ the electric
field.
If no magnetic field is present:
\f[
J = \sigma E
\f]
The electric field given by
\f[
E = \grad V
\f]
Therefore:
\f[
\frac{d(P)}{d(V)} = J \cdot E
= (sigma E) \cdot E
= (sigma \grad V) \cdot \grad V
\f]
Usage
Isotropic (scalar) electrical conductivity
\verbatim
jouleHeatingSourceCoeffs
{
anisotropicElectricalConductivity no;
// Optionally specify the conductivity as a function of
// temperature
// Note: if not supplied, this will be read from the time
// directory
sigma table
(
(273 1e5)
(1000 1e5)
);
}
\endverbatim
Anisotropic (vectorial) electrical conductivity
jouleHeatingSourceCoeffs
{
anisotropicElectricalConductivity yes;
coordinateSystem
{
type cartesian;
origin (0 0 0);
coordinateRotation
{
type axesRotation;
e1 (1 0 0);
e3 (0 0 1);
}
}
// Optionally specify sigma as a function of temperature
//sigma (31900 63800 127600);
//
//sigma table
//(
// (0 (0 0 0))
// (1000 (127600 127600 127600))
//);
}
Where:
\table
Property | Description | Required | Default
value
T | Name of temperature field | no | T
sigma | Electrical conductivity as a function of
temperature |no|
anisotropicElectricalConductivity | Anisotropic flag | yes |
\endtable
The electrical conductivity can be specified using either:
- If the \c sigma entry is present the electrical conductivity is
specified
as a function of temperature using a Function1 type
- If not present the sigma field will be read from file
- If the anisotropicElectricalConductivity flag is set to 'true',
sigma
should be specified as a vector quantity
e.g. to avoid excessive unphysical velocities generated during slamming events in
incompressible VoF simulations
Usage
Example usage:
limitU
{
type limitVelocity;
active yes;
limitVelocityCoeffs
{
selectionMode all;
max 100;
}
}
Description
Constrain the field values within a specified region.
For example to set the turbulence properties within a porous region:
\verbatim
porosityTurbulence
{
type scalarFixedValueConstraint;
active yes;
scalarFixedValueConstraintCoeffs
{
selectionMode cellZone;
cellZone porosity;
fieldValues
{
k 30.7;
epsilon 1.5;
}
}
}
\endverbatim
See tutorials/compressible/rhoSimpleFoam/angledDuctExplicitFixedCoeff
constant/fvOptions for an example of this fvOption in action.
The deprecated non-const tmp functionality is now on the compiler switch
NON_CONST_TMP which can be enabled by adding -DNON_CONST_TMP to EXE_INC
in the Make/options file. However, it is recommended to upgrade all
code to the new safer tmp by using the '.ref()' member function rather
than the non-const '()' dereference operator when non-const access to
the temporary object is required.
Please report any problems on Mantis.
Henry G. Weller
CFD Direct.
fvOptions are transferred to the database on construction using
fv::options::New which returns a reference. The same function can be
use for construction and lookup so that fvOptions are now entirely
demand-driven.
The abstract base-classes for fvOptions now reside in the finiteVolume
library simplifying compilation and linkage. The concrete
implementations of fvOptions are still in the single monolithic
fvOptions library but in the future this will be separated into smaller
libraries based on application area which may be linked at run-time in
the same manner as functionObjects.
Provides run-time selection of buoyancy sources for compressible solvers
Replaces the built-in buoyancy sources in XiFoam, reactingFoam and
rhoReactingFoam.
e.g. in constant/fvOptions specify
momentumSource
{
type buoyancyForce;
buoyancyForceCoeffs
{
fieldNames (U);
}
}
and optionally specify the buoyancy energy source in the enthalpy
equation:
energySource
{
type buoyancyEnergy;
buoyancyEnergyCoeffs
{
fieldNames (h);
}
}
or internal energy equation
energySource
{
type buoyancyEnergy;
buoyancyEnergyCoeffs
{
fieldNames (e);
}
}
by introducing rational base-classes rather than using the hideous
'switch' statement. Further rationalization of the cell-selection
mechanism will be implemented via an appropriate class hierarchy to
replace the remaining 'switch' statement.
Mesh-motion is currently handled very inefficiently for cellSets and not
at all for inter-region coupling. The former will be improved when the
cell-selection classes are written and the latter by making the
meshToMesh class a MeshObject after it has been corrected for mapFields.
fvOptions does not have the appropriate structure to support MRF as it
is based on option selection by user-specified fields whereas MRF MUST
be applied to all velocity fields in the particular solver. A
consequence of the particular design choices in fvOptions made it
difficult to support MRF for multiphase and it is easier to support
frame-related and field related options separately.
Currently the MRF functionality provided supports only rotations but
the structure will be generalized to support other frame motions
including linear acceleration, SRF rotation and 6DoF which will be
run-time selectable.
Example usage:
SBM
{
type tabulatedAccelerationSource;
active true;
selectionMode all;
tabulatedAccelerationSourceCoeffs
{
timeDataFileName "constant/acceleration.dat";
}
}
Where the file constant/acceleration.dat contains a list of tuples
containing time and a vector of the linear acceleration, angular
velocity and angular acceleration e.g.
100
(
(0 ((0 0 0) (0 0 0) (0 0 0)))
(0.001 ((-0.0001 0 4e-05) (5e-5 -0.0002 -3e-8) (0.24 -0.8 -1e-4)))
.
.
.
)
The old separate incompressible and compressible libraries have been removed.
Most of the commonly used RANS and LES models have been upgraded to the
new framework but there are a few missing which will be added over the
next few days, in particular the realizable k-epsilon model. Some of
the less common incompressible RANS models have been introduced into the
new library instantiated for incompressible flow only. If they prove to
be generally useful they can be templated for compressible and
multiphase application.
The Spalart-Allmaras DDES and IDDES models have been thoroughly
debugged, removing serious errors concerning the use of S rather than
Omega.
The compressible instances of the models have been augmented by a simple
backward-compatible eddyDiffusivity model for thermal transport based on
alphat and alphaEff. This will be replaced with a separate run-time
selectable thermal transport model framework in a few weeks.
For simplicity and ease of maintenance and further development the
turbulent transport and wall modeling is based on nut/nuEff rather than
mut/muEff for compressible models so that all forms of turbulence models
can use the same wall-functions and other BCs.
All turbulence model selection made in the constant/turbulenceProperties
dictionary with RAS and LES as sub-dictionaries rather than in separate
files which added huge complexity for multiphase.
All tutorials have been updated so study the changes and update your own
cases by comparison with similar cases provided.
Sorry for the inconvenience in the break in backward-compatibility but
this update to the turbulence modeling is an essential step in the
future of OpenFOAM to allow more models to be added and maintained for a
wider range of cases and physics. Over the next weeks and months more
turbulence models will be added of single and multiphase flow, more
additional sub-models and further development and testing of existing
models. I hope this brings benefits to all OpenFOAM users.
Henry G. Weller
